ITMI20011793A1 - ELECTROOPTIC LIQUID CRYSTAL FILM ON CONDUCTIVE POLYMER ELECTRODES AND PROCEDURE FOR ITS PREPARATION - Google Patents

Description

DESCRIPTION of the industrial invention entitled

"LIQUID CRYSTAL ELECTRO-OPTICAL FILM ON CONDUCTIVE POLYMER ELECTRODES AND PROCEDURE FOR ITS PREPARATION"

TEXT OF THE DESCRIPTION

The present invention relates to a liquid crystal (LC) electrooptical film on conductive polymeric electrodes (CP) and a process for its preparation. These LC electrooptical films consist of:

A polymer dispersed liquid crystal (PDLC) morphology having a discontinuous liquid crystal phase dispersed in a continuous polymer matrix;

• a liquid crystal dispersed polymer (LCDP) morphology, having a discontinuous polymeric phase dispersed in a continuous liquid crystal matrix;

• a polymeric network (PNLC) liquid crystal morphology, having a discontinuous anisotropic polymeric network structure (gel) dispersed in a continuous liquid crystal phase;

• a polymer-free liquid crystal (LC).

The above represents the industrial exploitation field of the invention.

Dispersed liquid crystal electrooptical films or polymers (PDLCs) are known. See US Patent 4,435,047 (P.S. Drzaic, "Liquid Crystal Dispersion" World Scintific Publishing Co., 1995; Kent State University) and European Patent Application 0927753 and US Patent 5843333

In a PDLC electrooptical film, a discontinuous liquid crystal phase is dispersed in a continuous polymer phase. PDLC electro-optic films can be employed in switchable windows, light modulators, display displays and other types of devices to control light transmission.

Liquid crystal composites dispersed in a polymeric matrix, such as polymer dispersed liquid crystal (PDLC) and nematic curvilinearly-aligned phase (NCAP) liquid crystal devices generally comprise drops of a biaxially biaxially birefringent nematic liquid crystal material dispersed in a clear polymer matrix. These devices are interesting in that they can be electrically controlled or switched between relatively translucent (i.e. photo-dispersing or near-opaque) and relatively transparent (i.e. phototransmitter) states. This switching is possible because the liquid crystal drops exhibit birefringence, i.e. optical anisotropy. All liquid crystals have two refractive indices: an extraordinary refractive index measured along the long axis of rigid rod-like liquid crystals and a smaller ordinary refractive index measured in a plane perpendicular to the long axis. Consequently, the drops scatter light strongly when they are randomly oriented in the matrix and the devices appear translucent (or nearly opaque). Upon application of either an electric field or a magnetic field, however, the long axes of the liquid crystal droplets align along the direction of the electric / magnetic field vector and transmit the light more directly.

If the refractive indices of the liquid crystal material and the polymer matrix are very close while in the aligned state induced by the field, the devices appear transparent. Thus, following the application of a magnetic electric field, for example, the device switches from a state in which it is translucent (almost opaque) to a state in which it is transparent. Upon removal of the magnetic electric field, the device returns to a translucent (opaque) state.

Devices containing composites of liquid crystals dispersed in a polymer matrix have been employed as photo valves, filters, shutters, information displays, and in architectural glass and windows.

In scientific research of PDLC technology, a phenomenon known as inverse morphology or morphology of microspheres was mentioned infrequently. In a reverse morphology system, the polymeric phase is dispersed in a continuous liquid crystal phase. Reverse morphology systems are more difficult to employ than typical PDLC systems, since the liquid crystal phase is not neatly encapsulated within the polymeric phase and there is often less polymer to provide mechanical strength to the film in a reverse morphology system.

Reverse morphology systems have already been previously described. Yamagishi et al. Proc. SPIE, 1080: 24-31 (1989) describe an inverse morphology system having a nematic liquid crystal and a memory effect. Nomura et al., J. Appl.Phys., 68 (6): 2922-2926 (1990) describe an electrooptical film with a nematic liquid crystal component, polymeric microspheres linked to a memory effect. These documents do not describe reverse morphology systems having no memory effect and they do not describe reverse morphology systems with a liquid crystal having cholesteric properties. See in particular the European patent application 0927753.

However, the above teachings are not free from drawbacks as they are manufactured on transparent electrodes comprising metal coatings (copper, silver, gold, bronze) or inorganic metal oxides (indium-tin oxide - ITO) on rigid glass or film supports. Flexible PET. This entails such a high cost as to substantially limit the possibilities of commercial development of the films described above.

In particular, in films on a rigid support they present preparation problems since the process tends to be discontinuous due to the very nature of the rigid electrodes which require a specific treatment for each of them. Furthermore, films with rigid electrodes do not adapt well to the situation in which a particularly light film is required or when a curved surface is required.

PET ITO flexible backed films are extremely expensive as coating with metals or metal oxides is extremely complex. Furthermore, the flexibility of the film obtained is limited and, due to greater bending, the film becomes brittle.

The object of the present invention is therefore to produce films which have a substantially lower cost, so as to allow a wide diffusion of the product.

Another object is to provide flexible films which can be wound on a roll without brittleness problems.

Another object is to provide films which are suitable for applications in which a curved film is required.

Another object is to easily allow coloring of the film, without the need to color the liquid crystal.

Another object is to provide a film in which the flexible electrodes are perfectly compatible with the liquid crystal-based state contained between the two electrodes.

These and other purposes are achieved by a liquid crystal electrooptical film comprising an electrooptical layer formed with a liquid crystal material and a conductive layer formed with polymeric material, in which said polymeric material is conductive and forms an electrode.

The invention further relates to a process for manufacturing a liquid crystal film on conductive polymeric electrodes comprising:

(a) providing a mixture of liquid crystal material and a prepolymer material;

(b) coating and laminating the mixture with a roll-to-roll technique between two flexible supports having conductive polymeric coatings;

(c) hardening the mixture with ultraviolet radiation, with heat, by evaporation of solvent or by cooling to form an electro-optical film.

The invention provides, according to another aspect, a method for producing a liquid crystal film on conductive polymeric electrodes comprising:

a method for producing a liquid crystal film on conductive polymeric electrodes comprising:

(a) provide a mixture of liquid crystal materials; (b) coating and laminating the mixture in a roll-to-roll technique between two plastic supports with conductive polymer coatings to form a polymer-free LC electro-optical device.

Preferably, the film according to the invention comprises a second conductive layer formed with polymeric material, in which said polymeric material is conductive and forms an electrode.

said film being flexible.

Preferably, said polymeric material is a polythiophene, a polyanion, and an organic compound dihydroxy or polyhydroxy.

Preferably, said polymeric material is a material of formula (I)

in which

R1 and R2 separately from each other represent hydrogen or a Cl-4 alkyl group, or together form an optionally substituted Cl-4 alkylene radical, or an optionally substituted cycloalkylene group, preferably a methylene radical optionally substituted by alkyl groups, an ethylene radical -1,2 optionally replaced by Cl-12 alkyl groups or phenolic groups, a 1,2 cyclohexylene radical, or a 1,3 propylene group.

The invention also relates to a curved display which can be produced with a film according to the invention and a curved display which can be produced with the method according to the invention. This is particularly facilitated by the fact that the invention allows for high flexibility and curvature.

The following text describes the process of preparing and manufacturing a liquid crystal electrooptical film device between rigid flexible conductive polymer (CP) supports using polymerization induced phase separation or "Polymerization Induced Phase Separation (PIPS) processes. solvent-induced phase or "Solvent Induced Phase Separation (SIPS)", and thermally induced phase separation or "Thermally Induced Phase Separation (TIPS)". Thermosetting, thermoplastic and UV-curable polymers and nematic and cholesteric liquid crystals have been used in Formulations and Preparation Processes The film preparation procedures employed were roll-to-roll coating and lamination techniques using either a laboratory coating device or a pilot plant system.

The invention provides a liquid crystal electrooptical film comprising a liquid crystal material and a polymeric material, wherein the electrooptical film has a normal morphology (PDLC), an inverse morphology (LCDP), a polymer network gel morphology (PNLC ) or a liquid crystal (LC), free of polymer, in which the liquid crystal material has nematic or cholesteric properties. The liquid crystal material may comprise a mixture of a chiral material in a nematic liquid crystal material; the liquid crystal material may comprise only a chiral liquid crystal material.

In one embodiment of the invention, the electrooptical film has substantially no memory effect; in another embodiment of the invention, the electrooptical film has a memory effect.

In one embodiment of the invention, the electrooptical film comprises a zero weight percentage of polymeric material relative to the total weight of the liquid crystal material. In other embodiments of the invention, the electrooptical film comprises more than zero weight percent of polymeric material relative to the total weight of liquid crystal material. In other embodiments of the invention, the electrooptical film comprises more than 10 percent or more by weight of polymeric material; 10 percent or more by weight of polymeric material; 30 percent or more by weight of polymeric material, or 60 percent or more by weight of polymeric material.

In one embodiment of the invention, the electrooptical film has the macro phase separation morphology. In other embodiments of the invention, the electrooptical film has the LC morphology separated into micron-sized phases. In another embodiment of the invention, the electrooptical film has the LC morphology separated into submicron-sized phases. In yet another embodiment of the invention, the electrooptical film has the morphology of individual microspheres. In yet another embodiment of the invention, the electrooptical film has the polymeric network (gel) morphology. Finally, in other embodiments of the invention, the electrooptical film has the cholesteric helical pitch structure.

The invention also provides a liquid crystal electrooptical film comprising a liquid crystal material and a polymeric material in which the electrooptical film has a reverse morphology and has substantially no memory effect.

The electro-optical film can comprise spacers such as microspheres, micro-rods or microfibers; in another embodiment, the electrooptical film does not comprise spacers. The microspheres formed in the process of the invention can replace spacers in some embodiments of the invention.

In other embodiments of the invention, the liquid crystal material has cholesteric properties. The liquid crystal material having cholesteric properties may comprise a nematic liquid crystal material and a chiral material; the liquid crystal material having cholesteric properties may comprise a chiral liquid crystal material. The liquid crystal material having cholesteric properties may be a cholesteric liquid crystal. The liquid crystal material can have nematic properties; the liquid crystal material may comprise a nematic liquid crystal.

In a preferred embodiment of the invention, the electrooptical film has a contrast ratio greater than 10, more preferably 12.

The electro-optical film can comprise spacers such as microspheres, micro-rods or microfibers of plastic or glass; in another embodiment, the electrooptical film does not comprise spacers. The microspheres formed in the process of the invention can replace spacers in some embodiments of the invention.

The invention provides a process for producing an electrooptical or liquid crystal dispersed polymer (PDLC) film comprising: (a) a mixture of liquid crystal material and a prepolymer material; (b) thermal hardening of the mixture with ultraviolet radiation, by evaporation of the solvent or by cooling; to form an electrooptical film with macro-drop, micro-drop or nano-drop morphologies.

The invention also provides a method for producing an electrooptical film or liquid crystal dispersed polymer (LCDP) comprising: (a) a mixture of a liquid crystal material and a prepolymer material; (b) thermal hardening of the mixture with ultraviolet radiation, by vaporization of the solvent or by cooling; to form an electrooptical film with a reverse morphology. The invention also provides a method for producing a polymeric mesh liquid crystal (PNLC) electrooptical film comprising: (a) a mixture of a liquid crystal material and a prepolymer material; (b) hardening of the mixture with ultraviolet radiation; to form an electrooptical film with a mesh gel morphology.

The invention also provides a method for producing an electrooptical liquid crystal (LC) film comprising: (a) a mixture of a cholesteric nematic liquid crystal material to form an electrooptical film with a homeotropic, homogeneous, cholesteric planar or focal conical structure .

In one embodiment of this process, the liquid crystal material has cholesteric properties. The liquid crystal material having cholesteric properties may comprise a nematic liquid crystal material and a chiral material; the liquid crystal material having cholesteric properties may comprise a chiral liquid crystal material.

In this process, the electrooptical film can have the morphology of macro phase separation, the morphology of individual microspheres, or the morphology of substantially joined microspheres. In one embodiment of this method, the electrooptical film has substantially no memory effect.

The invention also provides an electro-optical device comprising a source of electrical pulses and an electro-optical film according to the invention, in which the electro-optical film has a memory effect and the film is periodically subjected to an electrical pulse from the source to maintain transparency or the opacity of the film. By employing the effect of memory and periodic electrical pulses, the power consumption of the electrooptical device can be reduced.

Various phase separation processes can be employed to make PDLC, LCDP or PNLC electrooptical films on CP electrodes. These phase separation processes include the following.

1. Polymerization-induced phase separation (PIPS) In polymerization-induced phase separation, polymer aggregates spontaneously form in a continuous liquid crystal phase following separation of the liquid crystal and polymer phases. Phase separation is induced by causing the uncured polymeric material to polymerize. Phase separation by polymerization is particularly useful when prepolymer materials are miscible with low molecular weight liquid crystal compounds. A homogeneous solution is prepared by mixing the prepolymer with the liquid crystal. Polymerization achieved by a condensation reaction, as with epoxy resins, by free radical polymerization, as with a vinyl monomer catalyzed with a free radical initiator benzoyl peroxide, or by photo initiated polymerization. As polymerization progresses, polymer aggregates form a discontinuous phase within the continuous liquid crystal phase. The cure rate is controlled by the cure temperature for thermally cured polymers or by the light intensity for photochemical cure.

2. Thermally induced phase separation (TIPS). In thermally induced phase separation, a binary mixture of polymer and liquid crystal forms a solution at an elevated temperature. Cooling the solution causes phase separation. As with the previous process, the liquid crystal material forms a continuous phase which contains discontinuous polymer aggregates.

3. Solvent-induced phase separation (SIPS). In solvent-induced phase separation, a polymer, a liquid crystal and an organic solvent are mixed together and the solvent is evaporated. Evaporation of the solvent causes phase separation. Combinations of these phase separation processes may also be employed.

Polymers used in making the LC and polymer composite materials on CP electrodes are obtained from three categories, ie UV curable or UV curable polymers, thermoplastic polymers or thermosetting polymers.

The UV curable or UV curable resin may be any known or commercial mesogen and non-mesogen resin. UV curable polymers useful in the present invention are commercially available.

The thermoplastic resin can be any known resin. Thermoplastic polymers useful in the present invention include polyethylene; polypropylene; poly (1-butene); poly (4-methyl-1-pentene); polyisobutylene; polystyrene; polybutadiene; polychloroprene; poly (methyl methacrylate); poly (ethyl methacrylate); poly (n-butyl methacrylate); poly (vinyl acetate); poly (vinyl alcohol); poly (vinyl chloride); poly (vinylidene chloride); poly (vinyl fluoride); poly (vinylidene fluoride); poly (caprolactam); poly (hexamethylene adipamide); poly (ethylene terephthalate); polyoxymethylene; poly ethylene oxide); poly (propylene oxide); poly (phenylene oxide); bisphenol A polycarbonate; dimethyl polysiloxane; poly (N-vinylpyrrolidinone); poly (ethyleneimine); ethyl cellulose; methyl cellulose; hydroxyethyl cellulose; hydroxypropyl cellulose; sodium carboxymethyl cellulose; cellulose nitrate; cellulose acetate; polyacrylic acid and its salts; polymethacrylic acid and its salts; polyacrylamide; polyacrylonitrile; poly (methacrylonitrile); poly (caprolactone); phenoxy resins; 2-hydroxyethyl methacrylate polymers; 2-hydroxypropyl methacrylate polymers; polymers of acrylonitrile 2-hydroxyethylacrylate; polymers of acrylonitrile 2-hydroxypropyl methacrylate; ethylene-ethyl acrylate copolymers; ethylene-propylene copolymers; copolymers of ethylene vinyl acetate; vinyl chloride-vinyl acetate copolymers; styrene-butadiene copolymers; styrene-isoprene copolymers; styrene-acrylonitrile copolymers; styrene-methyl methacrylate copolymers; polyvinyl butyral; poly (methyl acrylate); poly (ethyl acrylate); poly (vinyl propionate); ethylene-acrylic acid copolymers and their salts; cellulose acetate; cellulose propionate; cellulose acetate-butyrate; poly (diallyl phthalate); poly (decamethylene adipamide); poly (11-aminoundecanoic acid); poly (12-aminodecanoic acid); poly (methyl vinyl ether); poly (isobutyl vinyl ether); poly (isobutyl methacrylate), and poly (isocyanate).

As noted above, thermosetting resins can be employed in the present invention. Thermosetting polymers undergo a polarization cure reaction in which they are transformed from a lower molecular weight composition with heat, with or without catalysts, hardeners, modifiers, and the like, into a higher molecular weight cured or cured thermosetting resin. Thermosetting is the operation of using heat to transform the lowest molecular weight precursor into the hardened or cured product. The temperature required to accomplish this depends on the time provided to the reaction, the catalysts employed, and the relative reactivities and complementary functional groups in the precursor. The thermosetting resin can be any known resin.

Resins with a thermosetting epoxy matrix that harden at temperatures from about 120 ° C to about 170 ° C or higher, are suitable for use in composite materials of liquid and polymer crystals, bismaleimide resins (BMI), phenolics, polyesters, PMR -15 polyimides, and terminated with acetylene, typical thermosetting resins of other performances, are also usable in LCDP devices. Other thermosetting resins such as thermosetting resins from acrylic resins, polyurethane resins, free radical induced hardening resins, and the like, can be used to produce LCDP composite materials. The typical thermosetting resin is a stage A resin, but, in some cases, it may be desirable to employ a stage B resin. A stage B resin will affect the viscosity of the resin formulation.

There are a variety of epoxies suitable for use in manufacturing LCPD composite materials. All epoxy resins begin with an epoxy precursor for a homopolymerization reaction that is catalytically initiated, or co-reacted with complementary functional compositions such as compounds with active hydrogen groups or other reactive groups capable of reacting with an epoxy resin to determine the increase in the molecular weight of the epoxy resin. The performance of the cured epoxy depends on the degree of functionality of the resin and the co-reactant material, the degree of aromaticity of the resin, the molecular weight of the epoxy resin and any co-reactants prior to the reaction, and the level of cure or cure of the resin. resin. The co-reactant can be a curing agent and / or hardener.

Liquid crystal materials which are useful in practicing the present invention include smectic, nematic, cholesteric, ferroelectric, as well as mesogenic organic metal materials. See PCT publication W095 / 01410 (Hakemi).

Typical organic classes of liquid crystal forming materials that can be employed include both aromatic and aliphatic organic compounds such as benzylidene anilines, generally prepared from the reaction of para-substituted benzaldehyde and para-substituted aniline; N- (p-alkoxybenzylidene) -p-aminostyrene, prepared by the reaction of the appropriate aldehyde with paminostyrene; derivatives of beta sitosterol; active amyl ester of cyano benzylidene amino cinnamate; compounds containing pphenylene such as p-phenylene p-alkoxybenzoates; aminoacetophenones; aminopropiophenones; phenylenediamines; chlorophenylenediamines; terphthals; ρ, ρ'-disubstituted diphenyl acetylenes; p-p'-disubstituted 1,4-diphenylbutadienes; ρ, ρ'-disubstituted phenylbenzoates; substituted phenyl alkyl carbonates and diphenyl carbonate; p-n-alkyl benzoic acids; p-n-alkoxy benzoic acids; and Schiff bases prepared from p-substituted benzaldehydes and compounds of the following types: pphenylenediamines, 4, 4'-diaminobiphenyls, 4-phenylazoanilines, naphthylamines, and naphthylenediamines.

Specific liquid crystal compounds include ethyl p-4-ethoxy-benzylidene aminocinnamate; ρ, ρ'-azoxybenzoic acid diethyl ester; N- (p-methoxy-benzylidene) -p-aminostyrene; N- (pbutoxybenzylinene) -p-aminostyrene; p-azoxyanisole; pesyloxybenzalazine; p-azoxy-phenetol; p-anisylidene-pbiphenylamine; p-ethoxybenzylidene-p-biphenylamine; p-anisilidenep-aminophenyl acetate; p-ethoxybenzylidene-p-anuninophenyl acetate; p-n-hexyloxybenzylidene-p-cuninophenyl acetate; p-nesoloxybenzylidene-p-aminophenyl acetate; deca-2,4-dienoic acid; 4,4 'di-n-heptoxyzoxybenzene; 4,4 'di-npentoxyzoxybenzene; 4,4 'di-n-butoxyzoxybenzene, 4,4'-diethoxy-azoxybenzene; undeca -2,4-dienoic acid; nona-2,4-dienoic acid; 4.4 'dimethoxystylbene; 2,5-di (pethoxybenzylidene) cyclopentanone; 2,7-di- (benzylideneinmino) fluorene; 2-p-methoxybenzylideneeunino-phenanthrene; 4-methoxy-4 "-nitro-p-ter phenyl; 4-p-methoxybenzylideneeuninobiphenyl; 4,4'-di (benzylideneamine) biphenyl; p-n-hexylbenzoic acid; p-npropoxybenzoic acid; trans-p-methoxycinxnmic acid; 6 -methoxy-2-naphtholic; p-phenylene di-p-anisate; p-phenylene di-pethoxybenzoate; p-phenylene di-p-n-hexyloxybenzoate; p-phenylene dip-n-heptyloxybenzoate; p-phenylene di-p-n-octyloxybenzoate; 1,4-bicyclo [2.2.2] octylene di-p-anisate; 1,4-bicyclo [2.2.2] octylenedi-p-anisate; 1,4-bicyclo [2.2.2] octylene di-p-noctyloxy- benzoate; trans-1,4-cyclohexylene di-p-n-butoxybenzoate; 4,4 '-di (p-methoxybensylideneamino) dibenzyl; p, p'-diacetoxystylbene; 1,2-di (p-methoxyphenyl) -acetylene; p-acid - (pacethoxiazo) benzoic; l, 4-di- (p-methoxyphenyl) -butadiene; panisal-p-anisidine; ρ, ρ'-dimethoxybenzal-l, 4, -naphthalendiamine; p-n-butylbenzoic acid; ρ, ρ'- di-n-nutyldiphenylpyridazine; p- (pcianobenzal) anisidine; p- (p-methoxybenzoxy benzoic acid, anisal-p-aminozobenzene; 1- (4'-anisalamino) -4-phenylazonaphthal neither; N- (p-methoxy-benzylidene) -p-n-butylaniline; N- {p-noctiloxybenzylidene) -p-n-butylaniline; p-anisilidene-pphenylazoaniline; N, N'-dibenzylidenebenzidine; N, N'-di (p-nesyloxybenzylidene) benzidine; p-bis (-eptyloxybenzoyloxy) benzene; p-n-propoxybenzoic acid; pn-butoxybenzoic acid; p-n-amyloxybenzoic acid; p-nesiloxybenzoic acid; p-n-heptyloxybenzoic acid; p-noctiloxybenzoic acid; butyl-p- (p-ethoxy-phenoxycarbonyl) phenylcarbonate; p- (p-ethoxy-phenylazo) - phenyleptanoate; 4 - [(p— hexyloxycarbonyl-oxybenzylidene) amino] -1-pentyloxybenzene; N-p- (pentyloxycarbo-nyloxy) benzylidene-p-anisidine; p - [(pbutoxyphenyl) azo] phenyl butyl carbonate; p- (p-ethoxyphenylazo) phenylhexanoate; p- (p-ethoxy-phenylazo) phenyl valerate; p - [(pethoxybenzylidene) amino] benzonitrile; p - [(P ~ methoxybenzylidene) amino] benzonitrile; ethyl P - [(P ~ methoxybenzylidene) amino cinnamate; p- (p-ethoxyphenyl-azo) -phenylcrotonate; p - [(p-methoxybenzylidene) amino] -phenyl p-toluate; p - [(p— methoxybenzylidene) amino] -phenylbenzoate; p - [(p— ethoxybenzylidene) ainmin] phenylbenzoate; N, N'-di (methoxybenzylidene) -a, α'-biptoluidine; p-anisalazine; 4-acetoxy-3-methoxycinnéunic acid; p-acetoxycinnamic acid; 4 '- [(ppetyloxycarbonyloxybenzylidene) cunmino-valerophenon in diethyl ρ, ρ'azoxydicinnamate; 4-butoxy-benzylidene-4 '-aminoacetophenone; 4-decyloxybenzylidene-4 '-aminoacetophenone; 4-dodecyloxybenzylidene-4 '-cunminoacetophenone; 4-ethyloxybenzylidene-4 '-aminoacetophenone; 4-heptyloxybenzylidene-4'-aminoacetophenone: 4-hexyloxybenzylidene-4 '-aminoacetophenone; 4-methoxybenzylidene-4 '-cunminoacetophenone; 4-nonyloxybenzylidene-4'-eunminoacetophenone; 4-octyloxybenzylidene-4'-aminoacetophenone; 4-pentyloxybenzylidene-4 '-cunminoacetophenone; 4-propoxybenzylidene-4 '-cunminoacetophenone; 4-butoxybenzylidene-4'-éuninopropiophenone; 4-heptyloxybenzylidene-4 '-aminopropiophenone; 4-hexyloxybenzylidene-4 '-aminopropiophenone; 4-methoxybenzylidene-4'-aminopro-pyophenone; 4-nonyloxybenzylidene-4'-aminopropiophenone; 4-octyloxybenzylidene-4 <1> -aminopropiophenone; 4-pentyloxybenzidene-4 <1> -ammonipropiophenone; 4-propoxybenzylidene-4 'eminopropiophenone; bis- (4-bromobenzylidene) -2-chloro-1,4-phenylenedieunine; bis- (4-chlorobenzylidene) -2-chloro-1,4-phenylenedieuranine; bis- (4-ndecyloxybenzylidene) -2-chloro-1,4-phenylenedieuranine; bis- (4-ndodecyloxybenzylidene) -2-chloro-1,4-phenylenediamine; bis- (4-nesyloxybenzylidene) -2-chloro-1,4-phenylenedieuranine; bis- (4-methoxybenzylidene) -2-chloro-1,4-phenylenediamine; bis- {4-nonyloxybenzylidene) -2-chloro-1,4-phenylenedieuranine; bis- (4-noctiloxybenzylidene) -2-chloro-1,4-phenylenedieuranine; bis- (4-npentyloxybenzylidene) -2-chloro-1,4-phenylenediamine; bis- (4-bromobenzylidene) -1,4-phenylenediamine; bis- (4-chlorobenzylidene) 1,4-phenylenediamine bis- {4-n-decyloxybenzylidene) -1, 4-phenylenediamine; bis- (4-n-dodecyloxybenzylidene) -1,4-phenylenediamine; bis- (4-fluorobenzylidene) -1,4-phenylenediamine; bis- (4-n-heptyloxybenzylidene) -1,4-phenylenediamine; bis- (4-nesyloxybenzylidene) -1,4-phenylenediamine; bis- (4-nnonyloxybenzylidene) -1,4-phenylenediamine; bis- (4-nesyloxybenzylidene) -1,4-phenylenediamine; bis- (4-nnonyloxybenzylidene) -1,4-phenylenediamine; bis- (4-noctiloxybenzylidene) -1,4-phenylenediamine; bis- (4-npentyloxybenzylidene) -1, 4-phenylenedicunine; teref tal-bis- (pbromoaniline); terephthal-bis- (p-chloroaniline); terephthal-bis- (pfluoroaniline); and terephthal-bis- (p-iodoaniline).

Liquid crystalline nematic materials suitable for use include: p-azoxyanisole, p-azoxyphenetol, pbutoxybenzoic acid; p-methoxy-cinnamic acid, butyl-p-anisilidene-péunminocinnamate, p-ethoxy-benzal-amino-a-methyl-cinnamic acid; 1,4-bis (p-ethoxybenzylidene) cyclohexanone, 4,4'-hexyloxybenzene, 4,4'-dieptyloxybenzene), anisal-p-amino-azo-benzene, anisaldazine, a-benzene-azo- (anisal-a ' -naphthylamine), η, η'-nonoxybenzetoluidine; generic group anilines (p-nalkoxybenzylidene-p-n-alkylanilines), such as p-methoxybenzylidene p <1> -n-butylaniline, p-n-butoxybenzylidene-p '-aminophenylacetate, p-n-octi-benzylideneproprionate-p' -methylamine aminophenylbutyrate, p-n-butoxybenzylidene-p-éuninophenylpeatoate and mixtures thereof. Conjugated cyanoorganic compounds that are useful are 7,7 ', 8,8'-tetracyanoquinodimethane (TCNQ), (2,4,7, -trinitro-9-fluorenylidene) -malono-nitrile (TFM), p- [N - (p'— methoxybenzylidene) amino] -n-butyl-benzene (MBBA), P- [N- (P '~ ethoxybenzylidene) amino] amino] -butylbenzene (EBBA), p- [N- (p'-methoxybenzyline ) amino] phenyl butyrate, n-butyl-p- (p '-ethoxyphenoxycarbonyl) phenylcarbonate, p-methoxy-p' -n-butylazoxybenzene, p-ethoxy-p'-n'-butylazobenzene, P- [N- (P , _ methoxybenzylidene) amino] benzonitrile (BBCA), P- [N- (P'-methoxybenzylidene) amino] benzonitrile (BBCA), P- [N- (p'-hexylbenzylidene) amino] benzonitrile (HBCA), pentii phenylmethoxy benzoate , pentylphenylpentyloxy benzoate, cyanophenylpentyl benzoate, cyanophenylptyloxy benzoate, cyanophenyloctyloxy benzoate, and cyanophenylmethoxy benzoate.

Desirable nematic liquid crystals frequently include cyanobiphenyls, and can be mixed with cyanoterphenyls and various esters. There are nematic-type liquid crystal blends commercially available, such as the "E7" liquid crystal blend (Licrilite® BL001, of E. Merck, Darmstadt, Germany, or its subsidiaries such as EM Industries, Hawthorne, N.Y. and Merck Industriai Chemical, Poole, England) which is a mixture of (by weight) 51% 4'-n-pentyl-n-cyanobiphenyl (5CB), 21% 4'-n-heptyl-n-cyanobiphenyl (7CB), 16% 4'- n-octoxy-4-cyanobiphenyl, and 12% 4'-n-pentyl-4'-n-pentyl-4-cyanoterphenyl and which has a transition temperature from the crystalline phase to the nematic liquid crystalline phase of -10 ° C and a transition temperature from the liquid crystalline phase to the isotropic phase of 60.5 ° C. Illustrative of other similar commercial liquid crystal blends are as follows.

E31 are mixtures of cyanobiphenyl and non-cyano biphenyl esters obtainable from E. Merck, supra, and having a transition temperature from the crystalline phase to the nematic crystalline phase of -9 ° C and a transition temperature from the liquid crystalline phase to the isotropic phase 61.5 ° C. E44 is a mixture of cyanobiphenyls, a cyanoterphenyl and a non-cyano biphenyl ester, obtainable from (E. Merck, supra,) and having a transition temperature from the crystalline phase to the nematic liquid crystalline phase of -60 ° C and a transition temperature from the liquid crystal phase to the isotropic phase of 100 ° C. E63, by E. Merck, supra, is a liquid crystal mixture that is similar to E7 with added clloesanes; it contains significant quantities of the commonly known component and liquid crystal 5CB, 7CB, lower quantities of 5CT, lower quantities of benzonitrile, 4- (4-propyl-1-cyclohexen-1-yl), commonly known as PCH3, lower quantities of 4-carbonitrile, 4 '(4-pentyl-1-cyclohexen-1-yl) -1, 1-biphenyl, commonly known as BCH5, and even smaller amounts of [1,1'-biphenyl] -4-carboxylic acid , 4'ethyl-4'-cyano [1,1'-biphenyl] -4-yl ether commonly known as DB71. K-12 is a 4-cyano-4'-bitylphenyl and has a transition temperature from the crystalline phase to the nematic liquid crystalline phase of 45 ° C. K-18 is a 4-cyano-4'hexylbiphenyl and has a transition temperature from the crystalline phase to the nematic liquid crystalline phase of 14.5 ° C and a transition temperature from the liquid crystalline phase to the isotropic phase of 29 ° C. K-21 is a 4-cyano-4'-heptylbiphenyl and has a transition temperature from the crystalline phase to the nematic liquid crystalline phase of 30 ° C. K-24 is a 4-cyano-4'-octylbiphenyl and has a transition temperature from the smectic phase A to the liquid crystalline phase of 21.5 ° C, a transition temperature from the smectic phase C to the nematic liquid crystalline phase of 33, 5 ° C, and a transition temperature from the nematic liquid crystalline phase to the isotropic phase of 40.5 ° C. M-15 is a 4-cyano-4'-pentoxybiphenyl and has a transition temperature from the crystalline phase to the nematic liquid crystalline phase of 48 ° C and a transition temperature from the liquid crystalline phase to the isotropic phase of 68 ° C. N-18 is a 4-cyano-4'-hexoxybiphenyl and has a transition temperature from the crystalline phase to the nematic liquid crystalline phase of 57 ° C and a transition temperature from the liquid crystalline phase to the isotropic phase of 75.5 ° C. M-24 is 4-cyano-4 '-octoxybiphenyl and has a transition temperature from the crystalline phase to the smectic liquid crystalline phase A of 54.5 ° C, a transition temperature from the smectic crystalline phase A to the nematic phase of 67.0 ° C and a transition temperature from the nematic to isotropic phase of 80.0 ° C. Other Licrilite® liquid crystal blends include BL003, BL004, BL009, BL011, BL012, BL032, BL036, BL037, BL045, BL046, ML-1001, ML-1002, as well as TL202, TL203, TL204 and TL205, all obtainable from E Merck, supra.

ROTN404, which was obtainable from Hoffman-LaRoche, Basel, Switzerland, and Nutley, N.J., is a mixture of liquid crystals similar to E7 but with pyrimidine additions. It contains approximately 30% by weight of 4-carbonitrile, 4'-pentyloxy-1, 1'-biphenyl, commonly known as 50CB, 14% by weight of 4-carbonitrile, 4'-octyloxy-1, 1'-biphenyl, commonly known as 80CB, 10 percent by weight of 4-carbonitrile-4 "-pentyl-1,1 ', 4', 1" -terphenyl, commonly known as 5CT, 10 percent by weight of 4- (4-pentyl-2 -pyrimidinyl) -benzonitrile, commonly known as RO-CP-7035, 20 percent by weight of 4- (4-heptyl-2-pyrimidimyl) -benzonitrile, commonly known as RO-CP-7037, and 15 percent by weight of 4 - [5- (4-butylphenyl) -2-pyrimiedinyl] benzonitrile, commonly known as RO-CM-7334.

ROTN-570, obtainable from Hoffman-LaRoche is a liquid crystal mixture of cyano biphenyl, which contains 51 percent by weight of 4-cyano-41-pentylbiphenyl, 25 percent by weight of 4-cyano-4 '-eptylbiphenyl, 16 percent by weight of 4-cyano-4'-octyloxybiphenyl, and 8 weight percent of 4-cyano-4'-pentyl-pterphenyl. Another desirable liquid crystal blend from Hof fman-LaRoches is TN0623. Other liquid crystals that may be used include those obtainable from Valiant Fine Chemicals, Yntai, China, under the designations of YM-1, YM-6, YM-7, YM-8, YM-9 and YM-63.

As mentioned above, cholesteric liquid crystals may also be employed in the invention. A convenient way to obtain a material with cholesteric properties is to add a chiral dopant to a nematic liquid crystal. Common chiral dopants include CB15, a pure chiral component from Merck, and cholesteryl acetate, obtainable from Aldrich. Current cholesteric liquid crystals may also be employed. Examples of cholesteric crystals include cholesteryl esters of saturated and unsaturated organic acids, substituted and unsubstituted, in particular cholesteryl esters of aliphatic acids from C1 to C22, silica monocarbons e.g. cholesteryl nonanoate, cholesterol crotonate, cholesterol chloroformate, cholesterol chlorodecanoate, cholesterol chloroecosanoate, cholesteryl butyrate, cholesteryl caprate, cholesterol oleate, cholesteryl linolate, cholesterol linolenate, cholesteryl laurate, cholesterol erucate, cholesteryl myristate, cholesteryl clupanodonate, oleyl cholesteryl carbonate, cholesteryl ethyl carbamate, dodecyl cholesteryl carbonate; unsubstituted or halogenated cholesterol esters of aryl, alkynaryl, aralkenyl, alkaryl and aralkyl organic acids, especially cholesteryl esters of those organic acids containing an aromatic fraction from 7 to 19 carbon atoms, such as cholesteryl p-chlorobenzoate, cholesteryl cinnamate; coleseryl ethers, for example cholesteryl decyl ether, cholesteryl lauryl ether, cholesteryl oleyl ether, etc.

The invention further contemplates an electro-optical device comprising an electro-optical film according to the present invention. The devices of the invention include a thermally, electrically, magnetically and / or electromagnetically addressable liquid crystal electrooptical cell which has a film according to the invention between two closely spaced electrodes in which the film is sensitive to a voltage applied between the electrodes, in such that the transmittance of light through the liquid crystal material is selectable depending on the resulting electric field strength, current flow, or charge passed through the cells. The cells typically contain sealing layers, backing layers of transparent electrically conductive film having sufficient support resistance to maintain the structural integrity of the cell, polarizing elements when desirable, and associated adhesives. Electrooptical liquid crystal cells can be conveniently fabricated by a variety of techniques known in the art.

The cell can comprise two plastic sheet electrodes, both made conductive by means of a conductive polymeric coating, such as Orgacon 577120/6, Orgacon 2149001/02 or Orgacon 2002/014, obtainable from AGFA (Belgium), applied on poly film -ethylene-terephthalate (PET) or polycarbonate (PC). Alternatively, an electrode of the electrooptical liquid crystal cells can derive from a conductive coating, such as Orgacon 577120/6, Orgacon 2149001/02 or Orgacon 2002/014, obtainable from AGFA, Belgium, or indium tin oxide (ITO) obtainable from ISF (Belgium) or CP Films (UK), applied to a poly-ethylene-terephthalate (PET) film, a carbonate film (PC) or to a glass plate. This conductive glass sheet and a conductive plastic sheet, at least one having a CP coating, can be used to form the cell. Furthermore, the cell may comprise two glass electrodes, at least one of them being made conductive by a coating of CP.

Example (1)

An electrooptical polymer dispersed liquid crystal (PDLC) film was prepared by a single step UV-PIPS process, preparing a homogeneous mixture of 45% (w / w) nematic liquid crystal BL036 (Merck, Germany), 47, 5% (w / w) of NOA65 curable or UV curable prepolymer (Norland Chemicals, USA), 4% (w / w) of (_), 2.5% (w / w) of acrylic acid and 1% ( p / p) of photoinitiator (Ciba Geigy, Switzerland) compared to NOA65. The mixture was mixed with a magnetic mixer at 50 ° C for about 10 minutes, and then applied as a coating between two PET plastic sheets with a thickness of 175 μ∑ each, coated with Orgacon 5771209/06 (AGFA, Belgium ), with a surface resistivity of 300- / L / □, and separated by plastic micro-spacers (Dodwell Hi-Tech / Sekisui, Japan) of 15 μπι. The film sandwich was prepared using the coating / lamination system at 50 ° C and was partially hardened or cured with a neon lamp. The pre-cured PDLC film was cooled to 20-25 ° C and then cured or cured with a high pressure mercury UV lamp (Helios Italquarts, Italy) at 120 Watt / cm for about 30 seconds. The electrooptical properties of this blue colored PDLC sample compared to those of a standard PDLC sample with ITO-PET electrodes are tabulated in the table below:

Example (21

A polymer dispersed liquid crystal electrooptical film (PDLC) was prepared by a single step UV-PIPS process by preparing a homogeneous mixture of 45%. (w / w) nematic liquid crystal BL036 (Merck, Germany), 47.5% (w / w) UV curable NOA65 prepolymer (Norland Chemicals, USA) 4% (W / P) DI Tinuvin 400 (.. .) of 2.5% (w / w) of acrylic acid and 1% (w / w) of photoinitiator (Ciba Geigy, Switzerland) compared to NOA65.

The mixture was mixed with a magnetic mixer at 50 ° C for about 10 minutes and then applied as a coating between two PET plastic sheets with a thickness of 175 μχη each, coated with Orgacon 2149001/02 (AGFA, Belgium) with resistivity surface of 600-Λ- / Q and separated by plastic micro-spacers (Dodwell Hi-Tech / Sekisu, Japan) with a thickness of 15 μιη. The film sandwich was prepared using a 50 ° C coating / lamination system and was partially cured and cured with a neon lamp. The pre-cured or pre-cured PDLC film was cooled to 20-25 ° C and was then cured-cured with a high pressure mercury UV lamp (Helios Italquartz, Italy) at 120 Watt / cm for about 30 seconds. The electrooptical properties of this blue colored PDLC sample compared to those of a standard PDLC sample with ITO-PET electrodes are shown in the following table:

* data was measured with a sine wave of 80V and 50Hz.

Example (3)

A polymer dispersed liquid crystal electrooptical film (PDLC) was prepared by a single step UV-PIPS process, preparing a homogeneous mixture of 45% (w / w) nematic liquid crystal BL036 (Marck, Germany), 47, 5% (w / w) of NOA65 UV curable prepolymer (Norland Chemicals, USA), 4% (w / w) of Tinuvin 400 (...) (w / w) of acrylic acid and 1% (w / w ) of photoinitiator (Ciba Geigy, Switzerland) compared to NOA65. The mixture was mixed with a magnetic mixer at 50 ° C for about 10 minutes and then applied as a coating between two PET plastic sheets with a thickness of 175 μπι each, coated with Orgacon 2002/014 (AGFA, Belgium), with surface resistivity of 2500-iV / □, and separated by plastic micro-spacers (Dodwell Hi-Tech / Sekisui, Japan) with a thickness of 15 μπι. The film sandwich was prepared using the 50 ° C coating / lamination system and was partially cured with a neon lamp. The pre-cured and pre-cured PDLC film was cooled to 20-25 ° C and then cured with a high pressure mercury UV lamp (Helios Italquartz, Italy) at 120 Watt / cm for about 30 seconds. The electrooptical properties of this blue colored PDLC sample compared to that of a standard PDLC sample with ITO-PET electrodes are shown in the table below:

* data was measured with a sine wave of 80V and 50Hz.

MATERIALS

1 - POLYMERS AND RESINS

EPON 828 THERMOSETTING MATERIALS (Shell epoxy resin)

DER 331 (Dow Chemical)

HELOXY (Interorgana reactive diluent)

CAPCURE 3-800 (curing agent from Henkel)

NOA65 UV CURABLE MATERIALS (Norland UV Resin)

SAM 114 (UV resin from Merck)

CN934D60 (Cray Valley UV Resin)

EBECRYL (UCE)

PIBMA THERMOPLASTIC MATERIALS (Aldrich Polyisobutyl Methacrylate)

PARALO ID B / 72 (hydroxy functional acrylic resin by Rohm & Haas)

QR 1033 (hydroxy-functional acrylic resin from BAYER)

N75 (BAYER polyisocyanate)

2 - LIQUID CRYSTALS

BL036 (Merck nematic blend)

E43 (Merck nematic blend)

E7 (Merck nematic blend)

TN0623 (Hoffman-LaRoche nematic blend)

YM1 (Valiant nematic blend)

3 - CHIRAL COMPOUNDS

CB15 (pure chiral component from Merck)

(Aldrich's chiral component) cholesteryl acetate

4 - CONDUCTIVE SUBSTRATES

ORGACON-PET * (AGFA-Belgium, d = 125, 175 μιη)

ITO-PET * (CPFilm- USA or ISF-Belgium, d = 175 μπι)

(PET = polyethylene terephthalate)

5 - SPACERS

Microbeads (d = 5-30 microns by Dodwell Hi-Tech)

Microfibers (d = 5-30 microns by Dodwell Hi-Tech)

The previous description is provided in order to describe embodiments of the invention and does not want to limit in any way the protective scope of the invention. It will be evident to those skilled in the art that various modifications and variations can be made in the LCDP films, in their uses and in the manufacturing processes without departing from the spirit and protective scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of the present invention provided that they fall within the protective scope of the appended claims and their equivalents.

The invention allows to achieve all the prefixed purposes, in particular:

1. CP electrodes are made by simpler and easier spin coating manufacturing processes than that of ITO metal or metal oxide coatings.

2. The production cost of CP electrodes on PET support, and therefore their commercial price, are at least 50% lower than those of conventional ITO-PET films.

3. CP-PET electronic films are much less brittle than ITO electrodes, which provides ample possibilities for making highly flexible electrooptical films and related devices for non-flat panel applications.

4. Unlike the conventional white aspects of PDLC, LCDP and PNLC devices made on ITO-PET media, LC electrooptical devices manufactured on CP-PET media are usually colored and therefore find their uses in other expanded fields of film applications. LC and related devices in which colored aspects are desirable.

The invention allows wide fields of application in the sectors of: construction, transport, information technology, signage, etc.

Claims (25)

CLAIMS 1. Liquid crystal electrooptical film comprising an electrooptical layer formed with a liquid crystal material and a conductive layer formed with polymeric material, wherein said polymeric material is conductive and forms an electrode. 2. A film according to claim 1 comprising a second conductive layer formed with polymeric material, wherein said polymeric material is conductive and forms an electrode, said film being flexible. 3. Film according to at least one of the preceding claims wherein said polymeric material is a polythiophene, a polyanion, and an organic compound dihydroxy or polyhydroxy. 4. Film according to at least one of the preceding claims in which said polymeric material is a material of formula (I) R1 and R2 separately from each other represent hydrogen or a Cl-4 alkyl group, or together form an optionally substituted Cl-4 alkylene radical, or an optionally substituted cycloalkylene group, preferably a methylene radical optionally substituted by alkyl groups, an ethylene radical -1,2 optionally replaced by Cl-12 alkyl groups or phenolic groups, a 1,2 cyclohexylene radical, or a 1,3 propylene group. 5. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical layer is a polymer dispersed liquid crystal system (PDLC). 6. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical layer is a liquid crystal dispersed polymer system (LCDP). Electro-optic film according to at least one of the preceding claims, wherein said electoptic layer is a polymer network liquid crystal system (PNLC). B. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical layer is a polymer-free liquid crystal (LC) system. Electro-optical film according to at least one of the preceding claims, wherein said liquid crystal material comprises nematic liquid crystal material and chiral material, preferably chiral. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises more than 1% by weight of polymeric material with respect to the total weight of liquid crystal material and polymeric material. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises 10% or more by weight of polymeric material with respect to the total weight of liquid crystal material and polymeric material. Electro-optical film according to at least one of the preceding claims, in said electro-optical film comprises 30% or more by weight of polymeric material with respect to the total weight of liquid crystal material and polymeric material. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises 50% or more by weight of polymeric material with respect to the total weight of liquid crystal material and polymeric material. Electro-optical film, according to at least one of the preceding claims, wherein the electro-optical film comprises two flexible conductive polymeric electrodes. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises two rigid conductive polymeric electrodes. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises a flexible conductive polymeric electrode and a rigid conductive polymeric electrode. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises a flexible conductive polymeric electrode and a flexible ITO electrode. 18. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises a flexible conductive polymeric electrode and a rigid ITO electrode. 19. Electro-optical film according to at least one of the preceding claims, wherein said electro-optical film comprises a rigid conductive polymeric electrode and a flexible ITO electrode. 20. A process for making a liquid crystal film on conductive polymeric electrodes comprising: (d) providing a mixture of liquid crystal material and a prepolymer material; (e) coating and laminating the mixture in a roll-to-roll technique between two flexible supports having conductive polymeric coatings; (f) hardening the mixture with ultraviolet radiation, with heat, by evaporation of solvent or by cooling to form an electro-optical film. 21. Process according to claim 20 wherein said electrooptical film is selected from a PDLC film, an LCDP film, a PNLC film. 22. A process for producing a liquid crystal film on conductive polymeric electrodes comprising: (c) providing a mixture of liquid crystal materials; (d) coating and laminating the mixture in a roll-to-roll technique between two plastic supports with conductive polymer coatings to form a polymer-free LC electro-optical device. 23. Process according to at least one of the preceding claims, wherein said liquid crystal material comprises a nematic liquid crystal material and some chiral material. 24. Curved display made with a film according to at least one of the preceding claims. 25. Curved display made with a method according to at least one of the preceding claims.